Shaft Seal Assembly

ABSTRACT

An illustrative embodiment of a multi-shaft seal assembly generally includes a first seal, a second seal, and a collar. In the illustrative embodiment the collar may be integrally formed with a portion of the first seal, and may serve to axially space the second seal from the first seal. The second seal may be formed with a cutaway therein to ensure proper clearance between the second seal and one of the shafts. Other embodiments of the multi-shaft seal assembly use a collar formed with the equipment housing or second seal. Still other embodiments include additional seals for additional shafts.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant states that this utility patent application is a continuationof and claims priority from U.S. patent application Ser. No. 13/917,877filed on Jun. 14, 2013, which application claims priority fromprovisional Pat. App. Nos. 61/659,714 filed on Jun. 14, 2012 and61/661,936 filed on Jun. 20, 2012, all of which are incorporated byreference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates to a shaft seal assembly with multipleembodiments. In certain embodiments, the shaft seal assembly may be usedas a product seal between a product vessel and a shaft therein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

No federal funds were used to create or develop the invention herein.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISK APPENDIX N/A BACKGROUND OF THE INVENTION

For years there have been a multitude of attempts and ideas forproviding a satisfactory seal when a rotatable shaft is angularlymisaligned resulting in run out of the shaft. Typically the solutionspresented have failed to provide an adequate seal while allowing for anacceptable amount of shaft misalignment during operation. The problem isespecially acute in product seals where the potential for shaft to boremisalignment may be maximized. A typical solution in the prior art is toincrease the operating clearance between the rotating shaft and sealingmembers to create a “loose” clearance or operating condition. “Loose”running for adjustment or response to operational conditions, especiallymisalignment of the shaft with respect to the stator or stationarymember, however, typically reduces or lowers the efficiency and efficacyof sealing members.

Labyrinth seals, for example, have been in common use for many years forapplication to sealing rotatable shafts. A few of the advantages oflabyrinth seals over contact seals are increased wear resistance,extended operating life and reduced power consumption during use.Labyrinth seals, however, also depend on a close and defined clearancewith the rotatable shaft for proper function. Shaft misalignment is alsoa problem with “contact” seals because the contact between the seal andmisaligned shaft typically results in greater wear. Abrasiveness of theproduct also affects the wear pattern and the useful life of the contactseals.

Prior attempts to use fluid pressure (either vapor or liquid) to sealboth liquid and solid materials in combination with sealing members suchas labyrinth seals or contact seals have not been entirely satisfactorybecause of the “tight” or low clearance necessary to create the requiredpressure differential between the seal and the product on the other sideof the seal (i.e., the tighter the seal, the lower the volume of fluidrequired to maintain the seal against the external pressure ofmaterial.) Another weakness in the prior art is that many product sealsexpose the movable intermeshed sealing faces or surfaces of the productseal to the product resulting in aggressive wear and poor reliability.Furthermore, for certain applications, the product seal may need to beremoved entirely from the shaft seal assembly for cleaning, because ofproduct exposure to the sealing faces or surfaces.

The prior art then has failed to provide a solution that allows both a“tight” running clearance between the seal members and the stationarymember for efficacious sealing and a “loose” running clearance foradjustment or response to operational conditions especially misalignmentof the rotatable shaft with respect to the stator or stationary member.

SUMMARY OF THE INVENTION

The present art offers improved shaft sealing and product sealperformance over the prior art. The shaft seal assembly solutiondisclosed and claimed herein allows both tight or low running clearancebetween seal members and the stationary member and a loose runningclearance for adjustment or response to operational conditionsespecially misalignment of a rotatable shaft with respect to the statoror stationary member.

As disclosed herein, the present art describes and provides for improvedfunction by allowing a labyrinth seal to adjust to radial, axial andangular movements of the shaft while maintaining a desiredshaft-to-labyrinth clearance. The present art also permits equalizationof pressure across the labyrinth pattern by permitting venting and thusimproved function over currently available designs. Additionally,sealing fluid (air, steam, gas or liquid) pressure may be appliedthrough the vent or port locations to establish an internal sealpressure greater than inboard or outboard pressure(over-pressurization). This enables the labyrinth to seal pressuredifferentials that may exist between the inboard and outboard sides ofthe seal. Pressurization of the internal portion of the shaft sealassembly effectively isolates the moving or engaging faces of the shaftseal assembly from contact with product by design and in combinationwith a pressurized fluid barrier.

It is therefore an object of the present invention to provide a shaftseal assembly for engagement with a housing which maintains its sealingintegrity with a shaft upon application of axial, angular or radialforce upon said shaft.

It is another object of the present invention to provide a shaft sealassembly that may be mounted to a vessel wall for engagement with ashaft which maintains its sealing integrity with a shaft during or inresponse to axial, angular or radial force movement of said shaft.

Other objects and features of the invention will become apparent fromthe following detailed description when read with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered limited of its scope, the invention will be describedand explained with additional specificity and detail through the use ofthe accompanying drawings.

FIG. 1 is a perspective exterior view of the shaft seal assembly.

FIG. 2 is an exterior end view of the shaft seal assembly with the shaftelement aligned.

FIG. 3 is a sectional view of a first embodiment of the shaft sealassembly, as shown in FIG. 2 and mounted to a housing.

FIG. 3A illustrates the first surface seal-shaft integrity duringangular and radial shaft alignment.

FIG. 3B illustrates second surface seal-shaft integrity during angularand radial shaft alignment.

FIG. 4 is an exterior end view with the shaft misaligned.

FIG. 5 is a sectional view of the first embodiment as shown in FIG. 3with both angular and radial misalignment of the shaft applied.

FIG. 5A illustrates first seal-shaft integrity allowed by articulationduring angular and radial shaft misalignment.

FIG. 5B illustrates second seal-shaft integrity allowed by articulationduring angular and radial shaft misalignment.

FIG. 6 is a sectional view of a second embodiment of the shaft sealassembly as shown in FIG. 2.

FIG. 7 is a sectional view of a third embodiment as shown in FIG. 2.

FIG. 8 is a perspective view of a fourth embodiment as mounted to avessel wall.

FIG. 9 is a cross-sectional of view of one embodiment of the shaft sealassembly with the shaft aligned with respect to the housing.

FIG. 10 is a cross-sectional view of another embodiment of the shaftseal assembly with the shaft aligned with respect to the housing.

FIG. 11 is a cross-sectional view of the embodiment shown in FIG. 10with the shaft misaligned with respect to the housing.

FIG. 12 is a cross-sectional view of the embodiment shown in FIG. 9 ofthe invention showing the shaft misaligned with respect to the housing.

FIG. 13 is a cross-sectional view of the embodiment shown in FIG. 9showing the shaft misaligned with respect to the housing.

FIG. 14 is a cross-sectional view of a third embodiment of the shaftseal assembly.

FIG. 14A is a detailed cross-sectional view of the interface between therotor and the shaft of the third embodiment of the shaft seal assembly.

FIG. 15 is a perspective view of a first embodiment of a multi-shaftseal assembly.

FIG. 15A is a perspective view of the embodiment of a multi-shaft sealassembly shown in FIG. 15 with the second seal removed for clarity.

FIG. 15B is a rear perspective view of the embodiment of a multi-shaftseal assembly shown in FIG. 15.

FIG. 16 is a plane vertical view of the embodiment shown in FIG. 15.

FIG. 17 is an axial, cross-sectional view of one of the seals shown inthe embodiment in FIG. 15.

FIG. 18A is a perspective view of another embodiment of a shaft sealassembly.

FIG. 18B is an axial, cross-sectional view of the embodiment of a shaftseal assembly shown in FIG. 18A.

FIG. 18C is an axial, exploded cross-sectional view of the embodiment ofa shaft seal assembly shown in FIG. 18A.

FIG. 18D is a detailed cross-sectional view of the embodiment of a shaftseal assembly shown in FIGS. 18A-18C wherein the shaft is verticallyoriented.

DETAILED DESCRIPTION-ELEMENT LISTING (FIGS. 1-8) Description Element No.Shaft  1 Fixed stator  2 Fixed stator (part-line)  2a Labyrinth seal  3Radiused face  3a Floating stator  4 Fluid return pathway  5 Shaft sealclearance  6 First o-ring  7 Anti-rotation pin  8 Vent  9 Anti-rotationgroove (floating stator) 10 Spherical interface 11 Anti-rotation pin 12Second o-ring 13 Labyrinth seal pattern grooves 14 First o-ring channel15 Cavity for anti-rotation device (fixed stator) 16 Axial face oflabyrinth seal 17 Axial face of floating stator 18 Second o-ring channel19 First clearance between floating stator/fixed stator 20 Secondclearance between floating stator/fixed stator 21 Throttle groove 22Labyrinth pattern annular groove 23 Sleeve 24 Shaft seal assembly 25Throttle (alignment skate) 26 Floating stator annular groove 27Labyrinth seal passage 28 Floating stator passage 29 Housing 30 Angle ofmisalignment 31 Bearings and bearing cavity 32 Mounting bolts 33 Vesselwall 34

DETAILED DESCRIPTION

Before the various embodiments of the present invention are explained indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangements ofcomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that phraseology and terminology used herein with referenceto device or element orientation (such as, for example, terms like“front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are onlyused to simplify description of the present invention, and do not aloneindicate or imply that the device or element referred to must have aparticular orientation. In addition, terms such as “first”, “second”,and “third” are used herein and in the appended claims for purposes ofdescription and are not intended to indicate or imply relativeimportance or significance.

FIGS. 1-5 provide a view of a first embodiment of the shaft sealassembly 25 that allows for sealing various lubricating solutions withinbearing housing 30. FIGS. 6 and 7 provide alternative embodiments of theshaft seal assembly 25 wherein sealing fluids are used. Applicant hereindefines sealing fluids to include both liquids and vapors. Applicantconsiders air, nitrogen, water and steam as well as any other fluidwhich may work with the proposed shaft seal assembly to provide apressurized fluid barrier for any and all embodiments disclosed hereinto be within the purview of the present disclosure. The gas or fluidchosen is based on process suitability with the product to be sealed.

FIG. 1 is a perspective exterior view of the shaft seal assembly 25arranged and engaged with a shaft 1 inserted through the fixed stator 2of shaft seal assembly 25. FIG. 2 is an exterior end view of the shaftseal assembly with shaft 1 aligned within the shaft seal assembly 25.

FIG. 3 is a sectional view of a first embodiment of the shaft sealassembly 25 shown in FIG. 2 illustrating the shaft seal assembly 25 as alabyrinth seal for retaining lubrication solution within the bearingcavity 32 of housing 30. The shaft 1 shown in FIG. 3 is the type whichmay experience radial, angular or axial movement relative to the fixedstator element or portion of the fixed stator 2 during rotation. Thefixed stator portion of the shaft seal assembly 25 may be flange-mountedor press-fit or attached by other means to a housing 30. The inventionwill also function with a rotating housing and stationary shaft. (Notshown) As required by the particular application, the shaft 1 is allowedto move freely in the axial direction in relation to the shaft sealassembly 25.

A labyrinth seal 3 having an interior surface is engaged with shaft 1. Adefined clearance 6 exists between the interior surface of saidlabyrinth seal 3 and the shaft 1. Opposite the interior surface of saidlabyrinth seal 3 is the radiused surface 3 a of said labyrinth seal 3.The radiused surface 3 a of the labyrinth seal 3 and the interior of thefloating stator 4 forms a spherical interface 11. O-ring channels 15 ando-rings 7 are disposed to cooperate with said radiused surface 3 a ofsaid labyrinth seal 3 to seal (or trap) fluid migration through, betweenand along engaged labyrinth seal 3 and floating stator 4 whilemaintaining spherical interface 11 which allows limited relativerotational movement (articulation) between labyrinth seal 3 and floatingstator 4. O-ring channels 15, as shown, are machined into the floatingstator 4 and positioned at the spherical interface 11 with labyrinthseal 3. O-ring channels 15 are annular and continuous in relation tolabyrinth seal 3. The o-ring channel 15 and o-ring 7 may also be placedin the labyrinth seal 3 adjacent the spherical interface 11. O-rings 7should be made of materials that are compatible with both the product tobe sealed and the preferred sealing fluid chosen. O-ring channels 15 ando-rings 7 are one possible combination of sealing means that may be usedwithin the shaft seal assembly 25 as recited in the claims.Strategically placed anti-rotation pin(s) 12 inserted into anti-rotationgrooves 10 limit relative rotational movement between labyrinth seal 3and floating stator 4. A plurality of anti-rotation grooves 10 and pins12 may be placed around the radius of the shaft 1. If the shaft sealassembly 25 is used in combination with a sealing fluid, strategicanti-rotation pins 12 may be removed allowing correspondinganti-rotation grooves 10 to serve as a fluid passage through vent 9 andlubricant return 5. (See FIG. 7) Additionally, the relationship of thediameters of anti-rotation pins 12 and anti-rotation grooves 10 may beselected to allow more or less angular misalignment of the shaft 1. Asmall diameter anti-rotation pin 12 used with a large diameteranti-rotation groove 10 would allow for greater relative movement of thelabyrinth seal 3 in relation to the floating stator 4 in response toangular misalignment of shaft 1. Labyrinth seal 3 is one possibleembodiment of a sealing means that may be used adjacent to the shaft 1within the shaft seal assembly 25 as recited in the claims.

A continuous annular channel is formed within fixed stator 2 and definedby clearance 20 and 21 as allowed between the exterior of said floatingstator 4 and said interior of said fixed stator 2 of shaft seal assembly25. The annular channel of fixed stator 2 is highlighted as A-A′ in FIG.2. The annular channel of the fixed stator has interior surfaces whichare substantially perpendicular to said shaft 1. The exterior surfacesof the floating stator 4, which is substantially encompassed within theannular channel of the fixed stator 2, cooperatively engage with thefirst and second interior perpendicular faces of the fixed stator 2. Aninner annular interface is formed by the first (shaft seal assemblyinboard side) perpendicular annular channel surface of the fixed stator2 engaging with the first (inboard side) perpendicular face of thefloating stator 4. An outer annular interface is formed by the second(shaft seal assembly outboard side) perpendicular annular interiorchannel surface of the fixed stator 2 engaging with the second (outboardside) perpendicular face of the floating stator 4. O-ring channels 19and o-rings 13 disposed therein cooperate with the surfaces of floatingstator 4 which are in perpendicular to relation to shaft 1 to sealing(or trap) fluid migration between and along engaged floating stator 4while allowing limited relative rotational movement between floatingstator 4 and fixed stator 2. Floating stator 4 and fixed stator 2 areone possible embodiment of cooperatively engaged sealing means that maybe used in combination with labyrinth seal 3 within the shaft sealassembly 25 as recited in the claims.

O-ring channels 19 are annular and continuous in relation to shaft 1.The o-ring channels 19 and o-rings 13 may be placed in the body of thefloating stator 4 instead of the fixed stator 2 (not shown) but must beplaced in similar proximal relation. O-rings 13 should be made ofmaterials that are compatible with both the product to be sealed and thepreferred sealing fluid chosen. O-ring channels 19 and o-rings 13 areone possible combination of sealing means that may be used within theshaft seal assembly 25 as recited in the claims.

Strategically placed anti-rotation pin(s) 8 inserted into anti-rotationgroove(s) 16 limit both relative radial and rotational movement betweenfloating stator 4 and interior side of fixed stator 2. A plurality ofanti-rotation grooves 16 and pins 8 may be placed around the radius ofthe shaft 1. The relationship of the diameters of anti-rotation pins 8and anti-rotation grooves 16 may also be selected to allow more or lessangular misalignment of the shaft. A small diameter anti-rotation pin 8and large diameter fixed stator anti-rotation groove allow for greaterrelative movement of the labyrinth seal 3 in response to angularmisalignment of shaft 1.

The labyrinth pattern seal grooves 14 may be pressure equalized byventing through one or more vents 9. If so desired, the vents may besupplied with a pressurized sealing fluid to over-pressurize thelabyrinth area 14 and shaft seal clearance 6 to increase the efficacy ofshaft seal assembly 25. A spherical interface 11 between the labyrinthseal 3 and the floating stator 4 allow for angular misalignment betweenthe shaft 1 and fixed stator 2. O-ring channels 19 are annular with theshaft 1 and, as shown, are machined into the fixed stator 2 andpositioned at the interface between the fixed stator 2 and floatingstator 4. O-ring channel 19 may also be placed in the floating stator 4for sealing contact with the fixed stator 2.

FIG. 3A illustrates seal-shaft integrity during angular and radial shaftalignment. This view highlights the alignment of the axial face 17 ofthe labyrinth seal 3 and the axial face 18 of the floating stator 4.Particular focus is drawn to the alignment of the axial faces 17 and 18at the spherical interface 11 between the floating stator 4 andlabyrinth 3. FIG. 3B illustrates the shaft-seal integrity during angularand radial shaft alignment at the surface opposite that shown in FIG.3A. This view highlights the alignment of the axial faces 17 and 18 oflabyrinth seal 3 and floating stator 4, respectively, for the oppositeportion of the shaft seal assembly 25 as shown in FIG. 3A. Thosepracticed in the arts will appreciate that because the shaft 1 and shaftseal assembly 25 are of a circular shape and nature, the surfaces areshown 360 degrees around shaft 1. Again, particular focus is drawn tothe alignment of the axial faces 17 and 18 at the spherical interface 11between the labyrinth seal 3 and floating stator 4. FIGS. 3A and 3B alsoillustrate the first defined clearance 20 between the floating stator 4and the fixed stator 2 and the second defined clearance 21 between thefloating stator 4 and fixed stator 2 and opposite the first definedclearance 20.

In FIGS. 2, 3, 3A and 3B, the shaft 1 is not experiencing radial,angular or axial movement and the width of the defined clearances 20 and21, which are substantially equal, indicate little movement ormisalignment upon the floating stator 4.

FIG. 4 is an exterior end view of the shaft seal assembly 25 with therotatable shaft 1 misaligned therein. FIG. 5 is a sectional view of thefirst embodiment of the shaft seal assembly 25 as shown in FIG. 3 withboth angular and radial misalignment of the shaft 1 applied. The shaft 1as shown in FIG. 5 is also of the type which may experience radial,angular or axial movement relative to the fixed stator 2 portion of theshaft seal assembly 25.

As shown at FIG. 5, the defined radial clearance 6 of labyrinth seal 3with shaft 1 has been maintained even though the angle of shaftmisalignment 31 has changed. The shaft 1 is still allowed to move freelyin the axial direction even though the angle of shaft misalignment 31has changed. The arrangement of the shaft seal assembly 25 allows thelabyrinth seal 3 to move with the floating stator 4 upon introduction ofradial movement of said shaft 1. The labyrinth seal 3 and floatingstator 4 are secured together by one or more compressed o-rings 7.Rotation of the labyrinth seal 3 within the floating stator 4 isprevented by anti-rotation means which may include a screws, pins orsimilar devices 12 to inhibit rotation. Rotation of the labyrinth seal 3and floating stator 4 assembly within the fixed stator 2 is prevented byanti-rotation pins 8. The pins as shown in FIGS. 3, 3A, 3B, 5, 6 and 7are one means of preventing rotation of the labyrinth seal 3 andfloating stator 4, as recited in the claims. Lubricant or other media tobe sealed by the labyrinth seal 3 may be collected and drained through aseries of one or more optional drains or lubricant return pathways 5.The labyrinth seal 3 may be pressure equalized by venting through one ormore vents 9. If so desired, the vents 9 may be supplied withpressurized air or other gas or fluid media to over-pressurize thelabyrinth seal 3 to increase seal efficacy.

The combination of close tolerances between the cooperatively engagedmechanical portions of the shaft seal assembly 25 and pressurizedsealing fluid inhibit product and contaminate contact with the internalsof the shaft seal assembly 25. The spherical interface 11 between thelabyrinth seal 3 and the floating stator 4 allow for angularmisalignment between the shaft 1 and fixed stator 2. O-ring channel 19and o-ring 13 disposed therein cooperate with the opposing faces of thefloating stator 4, which are substantially in perpendicular relation toshaft 1, to seal (or trap) fluid migration between and along engagedfloating stator 4 while allowing limited relative radial (vertical)movement between stator 4 and fixed stator 2.

FIG. 5A illustrates seal-shaft integrity allowed by the shaft sealassembly 25 during angular and radial shaft misalignment. This viewhighlights the offset or articulation of the axial faces 17 of thelabyrinth seal in relation the axial faces 18 of the floating stator 4for a first portion of the shaft seal assembly 25. Particular focus isdrawn to the offset of the axial faces 17 and 18 at the sphericalinterface 11 between labyrinth seal 3 and floating stator 4.

FIG. 5B illustrates seal-shaft integrity for a second surface, oppositethe first surface shown in FIG. 5A, during angular and radial shaftmisalignment. This view highlights that during misalignment of shaft 1,axial faces 17 and 18, of the labyrinth seal 3 and floating stator 4,respectively, are not aligned but instead move (articulate) in relationto each other. The shaft to seal clearance 6 is maintained in responseto the shaft misalignment and the overall seal integrity is notcompromised because the seal integrity of the floating stator 4 to fixedstator 2 and the floating stator 4 to labyrinth seal 3 are maintainedduring shaft misalignment. Those practiced in the arts will appreciatethat because the shaft 1 and shaft seal assembly 25 are of a circularshape and nature, the surfaces are shown 360 degrees around shaft 1.

FIGS. 5A and 5B also illustrate the first clearance or gap 20 betweenthe floating stator 4 and the fixed stator 2 and the second clearance orgap 21 between the floating stator 4 and fixed stator 2 and opposite thefirst clearance or gap 20.

In FIGS. 4, 5, 5A and 5B, the shaft 1 is experiencing radial, angular oraxial movement during rotation of the shaft 1 and the width of the gapsor clearances 20 and 21, have changed in response to said radial,angular or axial movement. (Compare to FIGS. 3, 3A and 3B.) The changein width of clearance 20 and 21 indicate the floating stator 4 has movedin response to the movement or angular misalignment of shaft 1. Theshaft seal assembly 25 allows articulation between axial faces 17 and18, maintenance of spherical interface 11 and radial movement at firstand second clearance, 20 and 21, respectively, while maintaining shaftseal clearance 6.

FIG. 6 is a sectional view of a second embodiment of the shaft sealassembly 25 as shown in FIG. 2 for over-pressurization with alternativelabyrinth seal pattern grooves 14. In this figure the labyrinth sealpattern grooves 14 are composed of a friction reducing substance such aspolytetrafluoroethylene (PTFE) that forms a close clearance to the shaft1. PTFE is also sometimes referred to as Teflon® which is manufacturedand marketed by Dupont. PTFE is a plastic with high chemical resistance,low and high temperature capability, resistance to weathering, lowfriction, electrical and thermal insulation, and “slipperiness.” The“slipperiness” of the material may also be defined as lubricous oradding a lubricous type quality to the material. Carbon or othermaterials may be substituted for PTFE to provide the necessary sealingqualities and lubricous qualities for labyrinth seal pattern grooves 14.

Pressurized sealing fluids are supplied to over-pressurize thelubricious labyrinth pattern 26 as shown in FIG. 6. The pressurizedsealing fluids make their way into the annular groove 23 of the throttle26 through one or more inlets. Throttle 26 is also referred to as “analignment skate” by those practiced in the arts. Throttle 26 allows thelabyrinth seal 3 to respond to movement of the shaft caused by themisalignment of the shaft 1. The pressurized sealing fluid escapes pastthe close clearance formed between the shaft 1 and labyrinth seal 3having throttle 26. The close proximity of the throttle 26 to the shaft1 also creates resistance to the sealing fluid flow over the shaft 1 andcauses pressure to build-up inside the annular groove 23. Floatingannular groove 27 in cooperation and connection with annular groove 23also provides an outlet for excess sealing fluid to be “bled” out ofshaft seal assembly 25 for pressure equalization or to maintain acontinuous fluid purge on the shaft sealing assembly 25 duringoperation. An advantage afforded by this aspect of the shaft sealingassembly 25 is its application wherein “clean-in place” product sealdecontamination procedures are preferred or required. Examples wouldinclude food grade applications.

FIG. 7 illustrates shaft seal assembly 25 with the anti-rotation pin 12removed to improve visualization of the inlets. These would typicallyexist, but are not limited to, a series of ports, inlets or passagesabout the circumference of the shaft seal assembly 25. FIG. 7 also showsthe shape and pattern of the labyrinth seal 3 may be varied. The shapeof throttles 26 may also be varied as shown by the square profile shownat throttle groove 22 in addition to the circular-type 26. Also notethat where direct contact with the shaft 1 is not desired, the shaftseal assembly 25 be used in combination with a separate sleeve 24 thatwould be attached by varied means to the shaft 1.

FIG. 8 shows that another embodiment of the present disclosure whereinthe shaft seal assembly 25 has been affixed to a vessel wall 34. Theshaft seal assembly 25 may be affixed to vessel wall 34 throughsecurement means such as mounting bolts 33 to ensure improved sealingwherein shaft 1 is subjected to angular misalignment. The mounting bolts33 and slots (not numbered) through the shaft seal assembly 25 exteriorare one means of mounting the shaft seal assembly 25, as recited in theclaims.

ELEMENT LISTING (FIGS. 9-18D) Description Element No. Shaft  10 Bearingisolator  18 Housing  19 Rotor  20 Stator 30, 31a Fixed stator  31Passage 40, 40a Spherical surface 50, 51  Clearance  52 Frictional seal 60 Flange unit  61a Center point  80 Conduit  99 Fluid 100 Pin 101Annular recess 102 Shaft seal assembly 200 Multi-shaft seal assembly 202Fastener 204 Aperture 206 Fixed stator 210 Main body 211 Face plate 212Pin recess  212a Inlet 214 Annular recess 216 Sealing member 218Floating stator 220 Radial exterior surface 222 Pin 224 First radialpassage 226 Concave surface 228 Rotor 230 Roller cavity 232 Cavity wall233 Roller 234 Second radial passage 236 Convex surface 238 First seal240 Collar 241 Collar lip  241a Collar cutaway 242 Second seal 250Cutaway 251 Shaft seal assembly 300 O-ring channel 302 O-ring 303Unitizing ring 304 Slip ring 305 First cooperating cavity  306a Secondcooperating cavity  306b Axial passage 307 Radial passage 308 Stator 310Stator body 311 Shoulder 312 Radial bore 313 Axial projection 314 Radialprojection 315 Axial channel 316 Radial channel 317 Unitizing ringchannel 318 Rotor 320 Rotor body 321 Rotor axial projection 324 Rotorradial projection 325 Rotor axial channel 326 Rotor radial channel 327Rotor unitizing ring channel 328

FIG. 9 shows another embodiment of a bearing isolator 18 mounted on ashaft 10. The shaft 10 extends through the bearing isolator 18 and thehousing 19. A source of gas or fluid, 100 which may include water orlubricant, may also be in communication with the bearing isolator 18 viaconduit 99. The rotor 20 is affixed to the shaft 10 by means by africtional seal 60, which may be configured as one or more o-rings. Therotor 20 follows the rotational movement of the shaft 10 because of thefrictional engagement of the seals 60. The passages 40 and 40 a are asshown but will not be described in detail here because such descriptionis already understood by those skilled in the art.

A pair of corresponding spherical surfaces 50 and 51 may be used tocreate a self-aligning radial clearance 52 between the rotor 20 and thestator 30 prior to, during, and after use. This clearance 52 may bemaintained at a constant value even as the shaft 10 becomes misalignedduring use. Various amounts and direction of misalignment between thecenterline of the shaft 10 and the housing 19 are illustrated in FIGS.11-13. An annular recess 102 between the stator 30 and fixed stator 31allows the bearing isolator 18 to accommodate a predetermined amount ofradial shaft displacement.

In the embodiments shown herein, the spherical surfaces 50, 51 have acenter point identical from the axial faces of both the rotor and stator20, 30, respectively. However, the spherical surfaces 50, 51 may beradially, and/or as shown, vertically spaced apart. These sphericalsurfaces 50, 51 may move radially in response to and/or in connectionwith and/or in concert with the radially positioning of other componentsof the bearing isolator 18. Typically, if the shaft 10 becomesmisaligned with respect to the housing 19, the rotor 20 willconsequently become misaligned with respect thereto, and then thespherical surfaces 50, 51 and/or the stator 30 moving radially withinthe annular recess of the fixed stator 31 may compensate for themisalignment.

FIGS. 11 and 13 illustrate that in one embodiment of the bearingisolator 18, the rotor 20 may move with respect to the stator 30, 31 asshaft 10 is misaligned with respect to housing 19 through theinteraction between spherical surfaces 50, 51 so as to ensure thedistances between the center points of the rotor 20 and stator 30 and afixed point on the housing 19 are constant.

In the embodiment of the bearing isolator 18 shown in FIGS. 10 & 11, thespherical surfaces 50, 51 may be positioned on a fixed stator 31 andstator 31 a rather than on the rotor 20 and stator 30. Still referringto FIGS. 10 & 11, this design allows the rotor 20 and stator 31 a tomove with respect to the fixed stator 31, flange unit 61 a, and housing19. The rotor 20, stator 31 a, and fixed stator 31 may move radiallywith respect to the flange unit 61 a (and consequently with respect tothe housing 19) as best shown in FIG. 11. In this embodiment of thebearing isolator 18 there is a very minimal amount of relative rotationbetween the spherical surfaces 50, 51.

The embodiment of the bearing isolator 18 shown in FIGS. 10 & 11 mayprovide for controlled radial movement of the fixed stator 31, stator 31a, and rotor 20 with respect to flange unit 61 a, which flange unit 61 amay be securely mounted to a housing 19. Rotational movement of thefixed stator 30 with respect to the flange unit 61 a may be prevented byanti-rotational pins 101. The fixed stator 31 may be frictionallysecured to the flange unit 61 a using a frictional seal 61, which may bemade of any material with sufficient elasticity and frictionalcharacteristics to hold the fixed stator 31 in a fixed radial positionwith respect to the flange unit 61 a but still be responsive to theradial forces when the shaft 10 is misaligned. Changes to the radialposition of the fixed stator 31, stator 31 a, and rotor 20 and theresulting positions thereof (as well as the resulting position of theinterface between the fixed stator 31 and stator 31 a) occurs until theradial force is fully accommodated or unit the maximum radialdisplacement of the bearing isolator 18 is reached.

In operation, the rotor 20 may be moved radially as shaft 10 ismisaligned with respect to the housing 19. Radial movement of thespherical surfaces 50, 51 between the stator 31 a and fixed stator mayresult from this pressure. FIG. 3 shows the resultant radial movement ofcenter point 80 as the shaft 10 is misaligned. During normal operation,the shaft 10 is typically horizontal with respect to the orientationshown in FIG. 3, as represented by line A. As the shaft 10 becomesmisaligned in a manner represented by line B, the center point 80 maymove to a point along line A″. As the shaft 10 becomes misaligned in amanner represented by line B′, the center point 80 may move to a pointalong line A′. However, in other shaft 10 misalignments, the radialpositions of the rotor 20, stator 30, and/or fixed stator 31 may beconstant and the spherical surfaces 50, 51 may compensate for the shaftmisalignment. From the preceding description it will be apparent thatthe bearing isolator 18 provides a constant seal around the shaft 10because the distance between the spherical surfaces 50, 51 is maintainedas a constant regardless of shaft 10 misalignment of a normal or designnature.

The physical dimensions of the spherical surfaces 50 and 51 may vary inlinear value and in distance from the center point 80, depending on thespecific application of the bearing isolator. These variations will beutilized to accommodate different sizes of shafts and seals anddifferent amounts of misalignment.

Axial Displacement Shaft Seal Assembly

Another embodiment of a shaft seal assembly 200 is shown in FIGS. 14 &14A. This embodiment is similar to the embodiment of the bearingisolator 18 described above and shown in FIGS. 9, 12, & 13. The shaftseal assembly 200 may include a fixed stator 210, floating stator 220,and a rotor 230, as shown. In the pictured embodiment, the rotor 230typically rotates with the shaft 10 while the fixed stator 210 andstator 220 do not. Accordingly, a rotational interface may exist betweena concave surface 228 of the floating stator 220 and a convex surface238 of the rotor 230. In other embodiments of the shaft seal assembly200 not pictured herein, but which embodiments are a corollary to theembodiment of the bearing isolator 18 shown in FIGS. 10 & 11, thefloating stator 220 may be configured with a convex surface thatcorresponds to a concave surface of the fixed stator. In such anembodiment, the rotational interface may be located at a position otherthan the interface between the concave and convex surfaces.

The embodiment of the shaft seal assembly 200 shown in FIGS. 14 & 14Aincludes a fixed stator 210 that may be securely mounted to a housing(not shown in FIGS. 14 & 14A) my any suitable methods and/or structure.The fixed stator 210 may include a main body 211 and a face plate 212that may be secured to one another. It is contemplated that a fixedstator 210 formed with a main body 211 and face plate 212 may facilitateease of installation of the shaft seal assembly 200 in certainapplications. In such applications, the main body 211 may be affixed tothe housing, the rotor 230 and floating stator 220 may be positionedappropriately, and then the face plate 212 may be secured to the mainbody 211.

The fixed stator 210 may be formed with an annular recess 216 into whicha portion of the floating stator 220 and/or rotor 230 may be positioned.A predetermined clearance between the radial exterior surface 222 of thefloating stator 220 and the interior surface of the annular recess 216may be selected to allow for relative radial movement between the fixedstator 210 and floating stator 220. At least one pin 224 may be affixedto the floating stator 220, and a portion of the pin 224 may extend intoa pin recess 212 a formed in the face plate 212 so as to prevent thefloating stator 220 from rotating with the rotor 230. The axialinterfaces between the floating stator 220 and fixed stator 210 may besealed with sealing members 218, which sealing members may be configuredas o-rings.

The floating stator 220 may also be formed with a concave surface 228 ina radial interior portion thereof. This concave surface 228 may form asemi-spherical interface with a corresponding convex surface 238 formedin the radial exterior portion of the rotor 230. Accordingly, the shaftseal assembly 200 shown in FIGS. 14 & 14A accommodates shaft 10misalignment and radial movement in an identical and/or similar mannerto that previously described for the bearing isolators 18.

The shaft seal assembly 200 may be configured to accommodate for axialmovement of the shaft 10. In the pictured embodiment this isaccomplished by forming at least one roller cavity 232 in the rotor 230adjacent the shaft 10. The illustrative embodiment includes two rollercavities 232 bound by a cavity wall 233 on either end thereof. At leastone roller 234 may be positioned in each roller cavity 232. Axialmovement of the shaft 10 may be accommodated by a roller 234 rollingalong the surface of the shaft 10 and within the roller cavity 232. Theillustrative embodiment includes two roller cavities 232 with one roller234 in each roller cavity 232, but the shaft seal assembly 200 is in noway limited by the number of roller cavities 232 and/or rollers 234associated therewith. The roller(s) 234 may be constructed of anysuitable material for the specific application of the shaft sealassembly 200. It is contemplated that an elastomeric material (e.g.,rubber, silicon rubber, other polymers) will be especially suitable formany applications.

The illustrative embodiment of the shaft seal assembly 200 also includesvarious fluid conduits for applying a sealing fluid to the shaft sealassembly 200. The fixed stator 210 is formed with an inlet 214 forintroduction of a sealing fluid to the shaft seal assembly 200. Theinlet 214 may be in fluid communication with one or more first radialpassages 226 in the floating stator 220, which first radial passages 226may in turn be in fluid communication with one or more second radialpassages 236 in the rotor 230. The roller(s) 234, roller cavity(ies)232, and cavity wall(s) 233 may be configured so that the sealing fluidintroduced to the inlet 214 exits the shaft seal assembly 200 from anarea between the rotor 230 and shaft 10 at a predetermined rate for agiven set of operation parameters (e.g., sealing fluid viscosity andpressure, shaft 10 rpm, etc.). The illustrative embodiment of the shaftseal assembly 200 may be formed with eight first radial passages 226formed in the floating stator 220, which correspond to eight secondradial passages 236 formed in the rotor 230, and the first radialpassages 226 and second radial passages 236 may be evenly spaced aboutthe circumference of the shaft seal assembly 200. However, in otherembodiments, different numbers, spacing, and/or configurations of thefirst radial passages 226 and/or second radial passages 236 may be usedwithout departing from the spirit and scope of the shaft seal assembly200 as disclosed and claimed herein.

In an embodiment of the shaft seal assembly 200 not pictured herein, butwhich embodiment is a corollary to that shown in FIGS. 10 & 11. It willbe apparent in light of the present disclosure that in such anembodiment, the rotor 20 will include at least one roller cavityadjacent the shaft 10 with at least one roller positioned therein ratherthan a frictional seal 60. As with the previous embodiments of the shaftseal assembly 200 described herein, the roller(s) may be configured torotatively couple the rotor 20 with the shaft 10. The rotor cavityand/or roller may be also be configured to allow the shaft 10 to moveaxially with respect to the shaft sealing assembly 200.

Multi-Shaft Seal Assembly

FIG. 15 provides a perspective view of a first embodiment a multi-shaftseal assembly 202. It is contemplated that a multi-shaft seal assembly202 may be especially useful in applications wherein two shafts 10 arepositioned in relative close proximity to one another, as shown for theillustrative embodiment pictured herein. The shafts 10 pictured hereinare also oriented such that the longitudinal axes thereof are parallelwith respect to one another. However, the multi-shaft seal assembly 202is not so limited, and other embodiments thereof exist for use withshafts 10 that are oriented differently than those pictured herein.

The illustrative embodiment of the multi-shaft seal assembly 202includes a first seal 240. A sealing portion of the first seal 240surrounds one shaft 10 and may be configured to operate in a mannersubstantially similar to other bearing isolators 18 and/or shaft sealassemblies 25, 200 disclosed herein or otherwise. A sealing portion of asecond seal 250 surrounds the other shaft 10 and also may be configuredto operate in a manner substantially similar to other bearing isolators18 and/or shaft seal assemblies 25, 200 disclosed herein or otherwise.For example, FIG. 17 provides an axial, cross-sectional view of a firstembodiment of the multi-shaft seal assembly 202, wherein both the firstand second seals 240, 250 are configured to operate in a mannersubstantially similar to the bearing isolator 18 shown in FIGS. 9-13.However, in other embodiments of the multi-shaft seal assembly 202,either the first or second seal 240, 250 may be differently configured.For example, the first and second seals 240, 250 may be configured likethe embodiment of a shaft seal assembly 200 shown in FIGS. 14 & 14A.Furthermore, in other embodiments of the multi-shaft seal 202, the firstseal 240 and second seal 250 may be configured differently from oneanother. For example, the first seal 240 may be configured to operate ina manner substantially similar to the bearing isolator 18 shown in FIGS.9-13 and the second seal 250 may be configured to operate in a mannersubstantially similar to the shaft seal assembly 200 shown in FIGS. 14 &14A. Accordingly, the specific internal configuration of either thefirst or second seal 240, 250 in no way limits the scope of themulti-shaft seal assembly 202 as disclosed herein.

As shown in FIG. 17, each seal 240, 250 may be configured to include afixed stator 210, floating stator 220, face plate 212, and a rotor 220,all of which are shown in FIG. 17 as being configured to operate in amanner substantially similar to the embodiment of a bearing isolator 18as shown in FIGS. 9-13, as previously mentioned. The rotor 230 may besecured to a shaft 10 such that the rotor 230 is coupled thereto androtates therewith in any suitable manner (several of which are describedabove for other embodiments of a bearing isolator 18 and/or shaft sealassemblies 25, 200). The fixed stator 210 may be secured to a housing 19in any suitable manner (several of which are described above for otherembodiments of a bearing isolator 18 and/or shaft seal assemblies 25,200 and which include but are not limited to mechanical fasteners 204,chemical adhesives, welding, interference fit, and/or combinationsthereof). One such suitable manner includes fasteners 204 as shown inFIGS. 15, 16, & 18 and corresponding apertures 206. The floating stator220 may be positioned within a portion of an annular recess 216 formedin the fixed stator 10, wherein the exterior axial boundary of theannular recess 216 may be defined by the interior surface of a faceplate 212, which may be engaged with the fixed stator 210 as previouslydescribed for other embodiments of the bearing isolator 18 and shaftseal assemblies 25, 200.

The fixed stator 210, floating stator 220, rotor 230, and/or face plate212 may cooperate to form a labyrinth seal. The fixed stator 210,floating stator 220, and/or the rotor 230 may be constructed in atwo-piece manner. As mentioned, in the illustrative embodiment, thefixed stator 210 may be configured to engage a face plate 212 via aplurality of fasteners 204, which may be distinct from the fasteners 204used to engage the fixed stator 210 with the housing 19. Other methodsand/or structures for engaging the face plate 212 with the fixed stator210 may be used without limitation. Additionally, an interface betweentwo portions of the rotor 230, two portions of the fixed stator 210, thefixed stator 210 and the floating stator 220, the rotor 230 and thefloating stator 220, and/or the rotor 230 and fixed stator 210 may besemi-spherical, as shown for the interface between the rotor 230 andfloating stator 220 for the embodiment pictured in FIG. 17. Furthermore,the seals 240, 250 may be formed with an inlet 214 therein, aspreviously described for the other embodiments of a bearing isolator 18and shaft seal assemblies 25, 200 disclosed herein to provide a sealingfluid to various passages within the multi-shaft seal assembly 202.

To accommodate two shafts 10 in relative close proximity, theillustrative embodiment of a multi-shaft seal assembly 202 employs aconfiguration in which the first and second seals 240, 250 areconfigured in a stacked arrangement (see FIGS. 16 & 17). That is, thefirst seal 240 may reside in a different radially oriented plane thanthat in which the second seal 250 resides. In the illustrativeembodiment, the planes are parallel with respect to one another.However, in other embodiments of the multi-shaft seal assembly 202 notpictured herein, the planes may have other orientations, whichorientations may be dependent at least in part on the orientation of theshafts 10 and/or housing 19.

A collar 241 may be secured to the housing 19 and/or the first seal 240to provide the proper axial spacing for the stacking arrangement of thefirst and second seals 240, 250. In the illustrative embodiment thecollar 241 may be formed separately from either the first seal 240 orthe housing 19, and later secured to the first seal 240 and/or housing19. As clearly shown in FIG. 15B, which provides a rear side perspectiveview of the illustrative embodiment of a multi-shaft seal assembly 202,the collar 241 may be formed with a collar cutaway 242 therein toaccommodate a portion of the second seal 250. As shown, the collarcutaway 242 may be configured with an angled portion to interface withthe exterior surface of the first seal 240.

In most applications, the surface prominently shown in FIG. 15B isadjacent a housing 19 during use of the multi-shaft seal assembly 202.Accordingly, the surface of the collar 241 and/or first seal 240adjacent the housing 19 may be formed with an o-ring channel therein toaccommodate an o-ring. An o-ring so positioned may serve to prevent airand/or other fluid from egress/ingress between the collar 241 andhousing 19 and/or between the first seal 240 and housing 19. Thespecific shape, dimensions, and/or configuration of the collar cutaway242 will vary from one embodiment of the twin-shaft seal assembly 202 tothe next, and may be at least dependent upon the spacing of the shafts10 and/or configuration of the first and second seals 240, 250, and istherefore in no way limiting to the scope of the multi-shaft sealassembly 202. As shown for the illustrative embodiment, the collar 241may be secured to the housing 19 via one or more fasteners 204 andcorresponding apertures 206. However, in other embodiments of themulti-shaft seal assembly 202 pictured herein, the collar 241 may beintegrally formed with a portion of the first seal 240. In still otherembodiments of the multi-shaft seal assembly 202 not pictured herein thecollar 241 may be integrally formed with the housing 19. In anotherembodiment of a multi-shaft seal assembly 202 not pictured herein thecollar 241 may be integrally formed with the second seal 250.Accordingly, the multi-shaft seal assembly 202 is not limited by thespecific configuration of the first collar 241 with respect to thehousing 19, first seal 240, and/or second seal 250.

The collar 241 may serve as an axial spacer between the equipmenthousing and the second seal 250 as clearly shown in FIGS. 16 & 17. Inthis embodiment, the axial dimension of the collar 241 is approximatelyequal to that of the first and second seals 240, 250. However, thecollar 240 may be formed with a collar lip 241 a into which a portion ofthe second seal 250 may seat, as shown in FIG. 17. Accordingly, inapplications wherein the radial dimension of the first and/or secondseal 240, 250 is too great for mounting thereof in the same radial planedue to the spacing of two adjacent shafts 10, the first and second seals240, 250 may be applied to the shafts 10 in an axially offsetconfiguration.

The multi-shaft seal assembly 202 may also include a cutaway 251 formedin a portion of the second seal 250. A cutaway 251 may be required toaccommodate certain configurations of adjacent shafts 10 wherein theshafts 10 are in relative close proximity to one another. As best shownin FIGS. 16 & 18, the configuration of shafts 10 in the illustrativeembodiment of the multi-shaft seal assembly 202 are in relatively closeproximity to one another such that the second seal 250 must be formedwith a cutaway 251 to accommodate adequate clearance with the shaft 10corresponding to the first seal 240. However, in other configurations ofadjacent shafts 10, the multi-shaft seal assembly 202 may not require acutaway 251. Accordingly, the multi-shaft seal assembly 202 is in no waylimited the presence, absence, and/or configuration of a cutaway 251.Generally, a cutaway 251 may reduce the radial dimension of the fixedstator 210 and/or face plate 212, as shown in FIG. 17. However, in otherconfigurations the cutaway 251 may alternatively or additional reducethe radial dimension of the floating stator 220 and/or rotor 230.

Although the illustrative embodiment of a multi-shaft seal assembly 202is configured to accommodate two shafts 10, other embodiments notpictured herein are configured to accommodate more than two shafts 10.Accordingly, the multi-shaft seal assembly 202 is not limited by thenumber of shafts 10 and/or seals 240, 250 associated therewith.

Additional Embodiments of a Shaft Seal Assembly

Another embodiment of a shaft seal assembly 200 is shown in perspectiveview in FIG. 18A. The illustrative embodiment shown in FIG. 18A includesboth a stator 310 and a rotor 320, which may rotate with respect to oneanother. The stator 310 may engage a housing 19 and surround a shaft 10that is rotatable with respect to and extends from the housing 19. Inthe illustrative embodiment, an o-ring 303 positioned in an o-ringchannel 302 formed in the stator 310 may be used to properly engage thestator 310 with the housing 19. However, any other suitable methodand/or structure for adequately engaging the stator 310 with the housing19 may be used with the shaft seal assembly 300 without departing fromthe spirit and scope as disclosed herein.

The rotor 320 may also surround the shaft 10, and it may also be engagedwith the shaft 10 so as to rotate therewith. In the illustrativeembodiment, an o-ring 303 positioned in an o-ring channel 302 formed inthe rotor 320 may be used to properly engage the rotor 320 with theshaft 10. However, any other suitable method and/or structure foradequately engaging the rotor 320 with the shaft 10 may be used with theshaft seal assembly 300 without departing from the spirit and scope asdisclosed herein. It is contemplated that this embodiment may beespecially suited for applications in which the shaft 10 and/or housing19 is oriented in a generally vertical arrangement and extends upwardwith respect to the housing 19, but the application of the shaft sealassembly 300 in no way limits the scope thereof. Furthermore, anyembodiments of a shaft seal assembly 25, 200, 202 may be configured withadvantageous features disclosed herein related to the embodiment of ashaft seal assembly 300 shown in FIGS. 18A-18D without limitation aloneor in combination.

The stator 310 may be formed with a stator body 311 having one or moreaxial projections 314 and/or radial projections 315 extending therefrom.Additionally, an axial projection 314 may extend from a radialprojection 315 or vice versa. The embodiment of a shaft seal assembly300 from FIG. 18A is shown in FIG. 18C with the stator 310 and rotor 320separated from one another. As shown, a shoulder 312 may be formed inthe stator body 311 to provide an interface with a housing 19. An o-ringchannel 302 may be formed in the shoulder 312 to accommodate an o-ring303 to facilitate proper engagement of the stator 310 and housing 19, aspreviously described above. Another o-ring channel 302 may be formed onthe interior surface of the stator body 311 adjacent the shaft 10. Aslip ring 305 may be positioned in this o-ring channel 302 to mitigateegress of lubricant from the housing 19 and ingress of contaminants tothe housing 19 via the space between the shaft 10 and stator 310. In oneembodiment, the slip ring 305 may be constructed of a low-frictionsynthetic material, such as PTFE. However, the specific materials ofconstruction of the slip ring 305 in no way limit the scope of thepresent disclosure. The stator body 311 may also be formed with one ormore radial bores 313 to facilitate an optional sealing fluid (e.g.,air, water, etc.) to further mitigate the egress and/or ingressdescribed above.

The rotor 320 may be formed with a rotor body 321 having one or morerotor axial projections 324 and/or rotor radial projections 325extending therefrom. Additionally, a rotor axial projection 324 mayextend from a rotor radial projection 325 or vice versa. A unitizingring 304 may reside partially within a unitizing ring channel 318 formedin the stator 310 and partially within a rotor unitizing ring channel328 and function to allow only a predetermined amount of relative axialmotion between the stator 310 and rotor 320. From a comparison of FIGS.18B and 18C, it will be apparent to those of ordinary skill in the artthat the various axial projections 314, radial projections 315, axialchannels 316, and/or radial channels 317 formed in the stator 310 maycooperate with various rotor axial projections 324, rotor radialprojections 325, rotor axial channels 326, and/or rotor radial channels327 to create a labyrinth seal having a laborious and/or circuitous pathof one or more axial channels 316 and/or one or more radial channels 317for egress of lubricants from the housing 19 and/or ingress ofcontaminants to the housing 19. An infinite number of configurations forthe various axial projections 314, radial projections 315, axialchannels 316, and/or radial channels 317 formed in the stator 310 maycooperate with various rotor axial projections 324, rotor radialprojections 325, rotor axial channels 326, and/or rotor radial channels327 exist, and accordingly, the specific number, existence, and/orconfiguration thereof in no way limits the scope of the shaft sealassembly 300 as disclosed and claimed herein.

In the illustrative embodiment of a shaft seal assembly 300 shownherein, the axial projections 314, radial projections 315, axialchannels 316, and/or radial channels 317 formed in the stator 310 maycooperate with various rotor axial projections 324, rotor radialprojections 325, rotor axial channels 326, and/or rotor radial channels327 may be configured to form a first cooperating cavity 306 a, a secondcooperating cavity 306 b, and an axial passage 307 for the firstpotential ingress point for contaminants. Referring to FIG. 18D, whichshows the illustrative embodiment of the shaft seal assembly 300 engagedwith a generally vertically oriented shaft 10 protruding upward from ahousing 19, the path contaminants must traverse to pass through theillustrative embodiment of the shaft seal assembly 300 is exceedinglytortuous. The only ingress point is a downwardly oriented terminus of anaxial passage 307, entry to which requires overcoming gravity. After aradial passage 308, contaminants are faced with another axial passage307 requiring overcoming gravity once again. This axial passage 307leads to a first cooperating cavity 306 a. Contaminants retained in thefirst cooperating cavity 306 a may simply drain downward therefrom viagravity. An axial passage 307 at the top of the first cooperating cavity306 a requires contaminants to completely fill the first cooperatingcavity 306 a and then overcome gravity to exit the first cooperatingcavity 306 a via the top axial passage 307.

A radial passage 308 may fluidly connect the axial passage 307 at thetop of the first cooperating cavity 306 a to a second cooperating cavity306 b. In the illustrative embodiment, three sides of the secondcooperating cavity 306 b may be formed via the rotor 320, whichgenerally rotates with the shaft 10 during use. Accordingly,contaminants reaching the second cooperating chamber 306 b may be flungradially outward due to centrifugal force imparted to the contaminantsvia rotation of the rotor 320. If contaminants within the secondcooperating chamber 306 b drain via gravity through an axial passage 307at the bottom of the second cooperating chamber 306 b, thosecontaminants must traverse a radial passage 308 prior to encountering acomparatively long radial passage 308 that leads to another axialpassage 307 adjacent the distal end of an axial projection 314 formed inthe stator 310. Another comparatively long radial passage 308 may be influid communication with the axial passage 307 adjacent the distal endof an axial projection 314 formed in the stator 310, the path throughwhich radial passage 308 may be interrupted by a unitizing ring 304occupying a portion of a unitizing ring channel 318 formed in the stator310 and a portion of a rotor unitizing ring channel 328. Shouldcontaminants traverse this radial passage 308, those contaminants mustalso traverse an axial passage 307 in fluid communication with thatradial passage 308 before contacting the shaft 10. To enter the housing19, contaminants positioned on the shaft 19 between the stator 310 androtor 320 must traverse a slip ring 305 that, in the illustrativeembodiment of a shaft seal assembly 300, may be positioned in an o-ringchannel 302 in the stator 310 adjacent the shaft 10. In the illustrativeembodiment of the shaft seal assembly 300 pictured herein, the varioustransitions between axial passages 307 and radial passages 308 may beconfigured as right angles. Additionally, all axial passages 307 may beparallel with one another and perpendicular to all radial passages 308.However, in other embodiments the axial passages 307 and/or radialpassages 308 may have different orientations without limitation. Forexample, in an embodiment not pictured herein, an axial passage 307 maybe angled at 45 degrees with respect to the rotational axis of the shaft10.

The materials used to construct the shaft seal assemblies 25, 200, 202,300 and various elements thereof will vary depending on the specificapplication, but it is contemplated that bronze, brass, stainless steel,or other non-sparking metals and/or metallic alloys and/or combinationsthereof will be especially useful for some applications. Accordingly,the above-referenced elements may be constructed of any material knownto those skilled in the art or later developed, which material isappropriate for the specific application of the shaft seal assembly,without departing from the spirit and scope of the shaft seal assemblies25, 200, 202, 300 as disclosed and claimed herein.

Having described the preferred embodiments, other features of the shaftseal assemblies 25, 200, 202, 300 will undoubtedly occur to those versedin the art, as will numerous modifications and alterations in theembodiments as illustrated herein, all of which may be achieved withoutdeparting from the spirit and scope of the shaft seal assemblies 200,202, 300 disclosed herein. Accordingly, the methods and embodimentspictured and described herein are for illustrative purposes only.

It should be noted that the shaft seal assemblies 25, 200, 202, 300 arenot limited to the specific embodiments pictured and described herein,but are intended to apply to all similar apparatuses and methods foraccommodating shaft(s) misalignment with respect to a housing, whetherthe misalignment is angular, radial, and/or axial. Modifications andalterations from the described embodiments will occur to those skilledin the art without departure from the spirit and scope of the shaft sealassemblies 25, 200, 202, 300.

What is claimed is:
 1. A multi-shaft seal assembly comprising: a. afirst seal engaged with a housing, wherein said first seal is configuredto surround a first shaft protruding from said housing, and wherein saidfirst seal functions to prevent ingress of contaminants to said housingand egress of lubricant from said housing; b. a collar engaged with saidhousing, wherein said collar is configured to surround at least aportion of a second shaft protruding from said housing; and, c. a secondseal engaged with said collar, wherein said second seal is configured tosurround said second shaft protruding from said housing, wherein saidfirst seal and said second seal are axially spaced from one another withrespect to the rotational axis of said first shaft, and wherein saidsecond seal functions to prevent ingress of contaminants to said housingand egress of lubricant from said housing.
 2. The multi-shaft sealassembly according to claim 1 wherein said collar is further defined ashaving an axial dimension substantially equal to that of said firstseal.
 3. The multi-shaft seal assembly according to claim 2 wherein saidfirst seal is further defined as residing in a first generally verticalplane, wherein said second seal is further defined as residing in asecond generally vertical plane, and wherein said first and secondgenerally vertical planes are spaced from one another by an amountapproximately equal to said axial dimension of said collar.
 4. Themulti-shaft seal assembly according to claim 3 wherein said second sealfurther comprises a cutaway, and wherein said cutaway accommodates aportion of said first shaft.
 5. The multi-shaft seal assembly accordingto claim 4 wherein said collar further comprises a collar cutaway, andwherein said collar cutaway accommodates a portion of said first seal.6. The multi-shaft seal assembly according to claim 5 wherein saidcollar further comprises a collar lip, and wherein said collar lip isconfigured to engage a peripheral surface of said second seal.
 7. Themulti-shaft seal assembly according to claim 6 wherein said first sealis further defined as comprising: a. a stator engaged with a housing; b.a rotor engaged with said first shaft, wherein said rotor rotates withsaid shaft.
 8. The multi-shaft seal assembly according to claim 7wherein said second seal is further defined as comprising: a. a statorengaged with a housing; b. a rotor engaged with said first shaft,wherein said rotor rotates with said shaft.
 9. The multi-shaft sealassembly according to claim 8 wherein an interface between said statorand said rotor of said first seal is defined as being semi-spherical inshape.
 10. A shaft seal assembly comprising: a. a stator configured forengagement with housing, said stator comprising: i. a stator body; ii. aprojection extending from said stator body; iii. a channel formed insaid stator; b. a rotor configured for engagement with a shaft, saidrotor comprising: i. a rotor body; ii. a projection extending from saidrotor body; iii. a channel formed in said rotor; and, c. wherein saidprojection extending from said stator body, said projection extendingfrom said rotor body, said channel formed in said stator, and saidchannel formed in said rotor cooperate to form a labyrinth seal having afirst cooperating cavity and a second cooperating cavity.
 11. The shaftseal assembly according to claim 10 wherein said first cooperatingcavity is further defined as having a generally rectangularcross-sectional shape.
 12. The shaft seal assembly according to claim 11wherein said second cooperating cavity is further defined as having agenerally rectangular cross-sectional shape.
 13. The shaft seal assemblyaccording to claim 12 wherein a length of said first cooperating cavityis generally perpendicularly oriented with respect to a length of saidsecond cooperating cavity.
 14. The shaft seal assembly according toclaim 13 further comprising a unitizing ring positioned at a point alongsaid labyrinth seal.
 15. The shaft seal assembly according to claim 14wherein said first cooperating groove is further defined as being formedfrom a radial recess in said stator and a corresponding radial recess insaid rotor.
 16. The shaft seal assembly according to claim 15 whereinsaid second cooperating groove is further defined as being formed froman axial projection of said stator and a second radial recess in saidrotor.